GLUCOSE UTILIZATION IN HUMAN EPIDERMIS - ITS CONTROL BY HEXOKINASE

[摘要] By comparing the in vivo concentrations of various substrates and inhibitors of hexokinase activitywith their demonstrable effects as shown in vitro, was possible to demonstrate the factors which account for the in vivo inhibition of kexokinase. This inhibition is due to the low concentration of ATP [adenosine triphosphate] and especially the high concentration of ADP [adenosine diphosphate] and inorganic phosphate. Since hexokinase acts as a gate to allow the free flow of glucose into the various metabolic channels of the cell, ADP and perhaps inorganic phosphate are in effect controlling the entire cellular economy. Any process which lowers the ADP or the phosphate concentration will cause a direct rise in the amount of glucose being utilized by the cell. Increased glycolysis and Krebs cycle functioning which utilize ADP and manufacture ATP will therefore increase the glucose utilization by the cell while conversely an increase in synthetic processes which break ATP down into ADP will tend to lower the utilization of glucose.